Why Does Stress Make Your Hair Turn Gray?
Have you ever noticed that politicians and CEOs develop grey hairs fairly quickly? Usually the growth of grey or white hairs accompanies old age. This is due to the natural depletion of melanocyte stem cells (MeSCs), which are responsible for the pigmentation of hair. A recent study by the lab of Ya-Chieh Hsu, professor at the Harvard Stem Cell Institute, discovered that acute stress caused mice to develop grey hairs by the same process as ageing—MeSC depletion. This could explain the premature greying of those who are subject to stress on a daily basis.
In their experiment, the researchers stimulated stress in mice by injecting them with a chemical called resiniferatoxin (RTX). RTX acts similarly to the compound in chili peppers that is responsible for the burning sensation of spice. In response to this stressor, the researchers observed that the sympathetic nervous system in mice became overstimulated and activated a “fight-or-flight” response, releasing a neurotransmitter called noradrenaline. Noradrenaline caused MeSCs to multiply and migrate, depleting the reservoir and leading to premature greying. Interestingly enough, if noradrenaline release was blocked, the mice’s hair did not lose color. This suggests that noradrenaline is necessary for greying.
While it may sound like bad news that your stress spawns grey hairs, scientists are deeply interested in further exploring the mechanisms of MeSC depletion. Future research may well discover a way to prevent both stress-induced and age-induced greying. To the next generation of politicians and leaders: do not fret- the age of hair dye may soon be over.
Zhang, B., Ma, S., Rachmin, I., He, M., Baral, P., Choi, S., Gonçalves, W. A., Shwartz, Y., Fast, E. M., Su, Y., Zon, L. I., Regev, A., Buenrostro, J. D., Cunha, T. M., Chiu, I. M., Fisher, D. E., & Hsu, Y.-C. (2020). Hyperactivation of sympathetic nerves drives depletion of melanocyte stem cells. Nature, 577(7792), 676–681. https://doi.org/10.1038/s41586-020-1935-3
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